Reliability, Availability, Maintainability, Safety (RAMS)

Reliability – The ability to start and continue to operate under designated operating conditions for a designated period expressed mathematically; Availability – The time in operation compared to the time out of service expressed mathematically; Maintainability – The ability of a system to be put back into service after a failure expressed mathematically; Safety – The probability of a hazardous event being initiated by the system expressed mathematically.